This invention is related to Dynamic Link Libraries (DLL) and a general and flexible operating system function for building and loading multi-attribute Dynamic Link Library packages.
As the hardware, operating system and application software evolve, the dynamic link library (DLL) users and providers, both from the operating system house and application developers, are faced with an increased demand in providing and employing multiple varieties of dynamic link libraries for different application attributes within a given operating system. When multiplied by the number of operating systems that application providers support, the task of building and maintaining multiple DLLs for multiple operating systems is becoming increasingly more difficult. For example, 64-bit computers and operating systems have been available for some time now and the 64-bit applications, and DLLs are on the rise, however, the majority of usage still employs legacy 32-bit applications.
In addition to the 64-bit and 32-bit application DLLs, there are a number of different attributes from various operating system environments that an application provider has to consider. For example, EBCDIC based and/or ASCII based operating systems require different DLLs. While it is technically feasible to design an application to be able to handle both EBCDIC and ASCII based operations, the programming logic is becoming very complicated, error prone, and susceptible to performance degradation. Another attribute for consideration is floating point format. While most operating systems support the IEEE 754 floating point, there are still a huge number of vendor software and customer applications depending on z/OS® Hex floating point support. Another key operating system attribute is the program linkage. For z/OS®, there are traditional operating system linkage and high performance linkage. These linkages employ different linkage conventions and different general-purpose register (GPR) considerations. It should readily be appreciated that the list of different attributes will potentially grow as a natural result of electronic computing evolution coupled with maintaining compatibility and interoperability that customers demand.
As the e-business evolves, the need for supporting heterogeneous operating environments becomes increasingly important. Application providers are more inclined to develop a common code base to support multiple operating environments. How to package these applications and DLLs is one of the many problems facing application providers in this emerging cross platform application/DLL environment. Therefore, what is needed is means for an operating system to provide support to facilitate the multi-attribute nature of applications and DLLs for future development.